1. Field of the Invention
The invention herein relates to vapor release devices/dispensers. More particularly it relates to small two-part dispensers with disposable fluid reservoirs and re-usable fluid pumping mechanisms.
2. Description of Related Art
Commodity fragrance releasers and pheromone dispensers must be economical in order to be deemed commercially feasible by potential consumers. Three such devices are described in U.S. Pat. No. 5,928,194 for “Self-contained liquid microdispenser” (Maget I), U.S. Pat. No. 6,383,165 for “System for achieving a controlled low emission rate for small volumes of liquid solutions” (Maget V) and in U.S. Pat. No. 7,681,809 for “Electrochemical dispenser” (Maget VI).
Most prior art dispensers include an integral battery-powered gas generation unit, such as described in U.S. patent application Ser. No. 12/413,546 for “Electrochemical Gas Generator and Cell Assembly,” as well as in Maget VI. The Ser. No. 12/413,546 device does not, however, embody a dispenser having two parts (one being replaceable).
One prior device does teach a two-part fluid dispenser—Maget VI, as well as the system taught by U.S. Pat. No. 5,938,640 for “Two-part fluid dispenser” (Maget II). The teachings of Maget V and Maget VI are incorporated herein by reference since devices are described therein that includes an elongated dispenser similar to the device described herein, but with the following important distinctions: (i) fluid release in the prior system is from the top of the elongated reservoir and not the bottom, and (ii) the pumping mechanism of Maget V is an integral part of the disposable releaser.
Another important difference and improvement over Maget VI is the re-usable feature of the driver. While the fluid reservoir will require regular replenishment, the gas generator will not. Since the gas generator has a long service life (several years), the driver can be expected to operate up until the exhaustion of the onboard battery capacity. Even then, replacing the onboard batteries will provide another gas generator operating cycle. Therefore the cost per use of the driver is amortized over the multiple uses of the driver (i.e. multiple battery replacements and fluid replenishments.)
Since the fluid reservoir of the instant design is based upon a plastic syringe, the cost of replacement of the disposable component is expected to be as low as that of plastic syringes, a commodity product, that are produced in billions of units/year by the health care industry.
While it may seem trivial, to place the syringe with the distal end pointing downward, the reader is assured that this is not the case. In fact, by employing this configuration, all of the fluid can be eventually evacuated from the syringe barrel, whereas in the device of Maget VI, some of the liquid would be entrapped at the base of the elongated reservoir. Furthermore, compression of the bladder of the Maget VI device requires ever-increasing forces (pressures) to expel the fluid or ever-decreasing delivery rates, since the bladder eventually needs to collapse completely in order to surrender the contents that can be trapped in the bladder folds. In contrast, in the present invention, the bladder expands outward, with its outer dimensions being confined by the rigid syringe wall. Gravity assists the syringe driver in forcing the liquid contents towards the distal end.
Similarly, replacing the fluid receiver of Maget V with a porous plastic cup of the present invention facilitates the attachment of the fluid emanation surface to the syringe. The combination of an airtight bladder and an airtight generator render it possible to hold the syringe “upside-down” without any loss of fluid. Additionally, fluid stream discontinuity between the Luer tip and the porous receiver prevents fluid “streaming” (capillary extraction of fluid from the syringe) as well as preventing the introduction of ambient air into the syringe. If either of these were permitted, it would be impossible to control the fluid delivery rate, and therefore the rate of emanation. Finally, the orientation of the dispenser allows for the solar cells to be mounted to the top of the gas generator and still be exposed to sunlight.